Dr. Michael Brown's research program with this award will provide a unique window into the time-variable structure and dynamics of the poorly understood atmosphere of Titan. This window will come at a critical time, when imminent arrival of the Cassini spacecraft will soon focus intense scientific scrutiny on the satellite. The projects take advantage of the Dr. Brown's recent detection of small clouds near the south pole of Titan and of two unique observational capabilities available to Dr. Brown to vastly expand our currently minuscule knowledge of clouds and weather on Titan. The first unique capability will be the ability to provide the first ever daily monitoring of global-averaged cloud formation and dissipation on Titan using a proven method on a new dedicated robotic observatory run by Dr. Brown. The robotic observatory will be able to detect the existence of even relatively small clouds on Titan on an ~hourly basis throughout the observing season. With five total years of observations acquired by the end of the award period, fundamental questions about cloud activity will be able to be addressed for the first time, such as: What are the timescales for formation and dissipation of clouds of the smallest to the largest sizes seen? Is the current period of frequent cloudiness related to the recent southern summer solstice? Are clouds preferentially present at particular Titan longitudes?
The second unique capability will be the ability to obtain high spatial-resolution adaptive optics images and spectra frequently throughout each observing season using a newly implemented target-of-opportunity interrupt mode at the Keck and Palomar observatories. Rather than obtaining infrequent observations at pre-determined times, as would be typical with standard astronomical scheduling, the target-of-opportunity interrupt mode allows observations to be obtained at times dictated by the cloud activity level on Titan (which we will know from the robotic monitoring) and allows for a large number of short blocks of time. With these frequent targeted observations, a full range of cloud conditions on Titan will be able to be observed that would otherwise take many years of continuous pre-scheduled observations to obtain. These data will allow the first ever understanding of the latitude of cloud formation and dissipation, seasonal changes in these latitudes, wind speeds on Titan, the growth and decay lifetimes of individual clouds, and the dynamics of infrequent hurricane-scale storms. Together these projects will provide the first long term quantitative data on the formation, evolution, and dissipation of the poorly understood clouds on Titan.
These activities will have a major impact on the education and training of all of the students and post-doctoral scholars involved. In particular, this project will form the basis of the Ph.D. thesis of a Caltech graduate student. Dr. Brown has a strong commitment to the education and training of women and underrepresented minorities, as is demonstrated by the students currently in his research group. A major aspect of the proposed work will be commissioning and gaining experience using a robotic telescope soon to be installed at Palomar Observatory. Once commissioned, this telescope will be available for all of the research and teaching activities of Dr. Brown, including, in particular, undergraduate students joining the group for the summer through Caltech's Summer Undergraduate Research Foundation (SURF) program. Moreover, Dr. Brown is working with Scitech, the manufacturer of the robotic telescope, to help define and refine priorities for astronomical usage of automated telescopes in the hopes that astronomers will finally be able to have access to off-the-shelf turnkey robotic telescope facilities for a wide variety of usages. ***
